2017 Vol. 48 No. 2
2017, 48(2): 125-134.
DOI: 10.11665/j.issn.1000-5048.20170201
Abstract：
Type 2 diabetes, a glucose and lipid metabolism disorder accompanied by chronic multiple organ damage, has become a huge threat to human health. α/β hydrolase domain-6(ABHD6)regulates the insulin release negatively by hydrolyzing monoacylglycerol. Small molecule ABHD6 inhibitors have been proven to lower blood-glucose and regulates energy homeostasis, which is a potential candidate for the treatment of type 2 diabetes. This paper introduced the ABHD6 signaling pathway and its mechanism, then reviewed the progress of small molecule ABHD6 inhibitors with different structures in recent years, and analyzed the structure activity relationship.
Type 2 diabetes, a glucose and lipid metabolism disorder accompanied by chronic multiple organ damage, has become a huge threat to human health. α/β hydrolase domain-6(ABHD6)regulates the insulin release negatively by hydrolyzing monoacylglycerol. Small molecule ABHD6 inhibitors have been proven to lower blood-glucose and regulates energy homeostasis, which is a potential candidate for the treatment of type 2 diabetes. This paper introduced the ABHD6 signaling pathway and its mechanism, then reviewed the progress of small molecule ABHD6 inhibitors with different structures in recent years, and analyzed the structure activity relationship.
2017, 48(2): 135-141.
DOI: 10.11665/j.issn.1000-5048.20170202
Abstract：
As children are extremely sensitive to the bad taste of medicine, they have poor compliance with the bitter medicine. It is of great importance to develop the approaches of taste masking for the research of paediatric drug formulations. Besides, taste masking technology is one of the main barrier to develop children pharmaceutic preparation. This article provides an overview of the advance in taste masking technology of oral paediatric medicine in recent years, and introduces five types of taste masking technology in terms of drug, preparation and the bitter taste transduction, including principle and characteristics of these approaches, as well as their application in formulations, so as to provide some references for the development of paediatric medicine.
As children are extremely sensitive to the bad taste of medicine, they have poor compliance with the bitter medicine. It is of great importance to develop the approaches of taste masking for the research of paediatric drug formulations. Besides, taste masking technology is one of the main barrier to develop children pharmaceutic preparation. This article provides an overview of the advance in taste masking technology of oral paediatric medicine in recent years, and introduces five types of taste masking technology in terms of drug, preparation and the bitter taste transduction, including principle and characteristics of these approaches, as well as their application in formulations, so as to provide some references for the development of paediatric medicine.
2017, 48(2): 142-149.
DOI: 10.11665/j.issn.1000-5048.20170203
Abstract：
Biodegradable and biocompatible functional polymers show high potential as novel drug carriers in disease diagnosis and therapy. Recently, protein drugs have brought about major breakthroughs in the treatment of various diseases including cancer, while the development of carrier technology is relatively delayed. This article reviews recent advances in biodegradable functional polymers as protein drug nanocarriers. Additionally, we have discussed the perspective of developing new generations of biocompatible and functional polymers.
Biodegradable and biocompatible functional polymers show high potential as novel drug carriers in disease diagnosis and therapy. Recently, protein drugs have brought about major breakthroughs in the treatment of various diseases including cancer, while the development of carrier technology is relatively delayed. This article reviews recent advances in biodegradable functional polymers as protein drug nanocarriers. Additionally, we have discussed the perspective of developing new generations of biocompatible and functional polymers.
2017, 48(2): 150-156.
DOI: 10.11665/j.issn.1000-5048.20170204
Abstract：
A series of 4-phenyl-pyrrolo［2, 3-d］pyrimidine derivatives were synthesized through modifying the structure of the lead compound ruxolitinib by molecular hybridization strategy. It was synthesized from pyrimidine-4, 6-diol by Vilsmeier-Haack reaction, SNAr reaction, cyclized, dehydration, Suzuki coupling and finally acylated to give 12 new compounds( 12a - 12l ). All structures of the synthesized compounds were confirmed by 1H NMR, 13C NMR, and HRMS analysis. The biological activities were evaluated in vitro. Their JAK2 inhibitory activities were studied using JAK2 enzymatic and TF1-GMCSF cellular assays. The results indicated that compounds 12b , 12e and 12h showed moderate activity. The anti-tumor activities were studied against JAK2-independent A549 cell line by the MTT assay. Results showed that the title compounds exhibited potent antiproliferative effect on A549, especially compound 12c (IC50=0. 12 μmol/L), suggesting that this series compounds might be promising anti-tumor agents for futher investigation.
A series of 4-phenyl-pyrrolo［2, 3-d］pyrimidine derivatives were synthesized through modifying the structure of the lead compound ruxolitinib by molecular hybridization strategy. It was synthesized from pyrimidine-4, 6-diol by Vilsmeier-Haack reaction, SNAr reaction, cyclized, dehydration, Suzuki coupling and finally acylated to give 12 new compounds( 12a - 12l ). All structures of the synthesized compounds were confirmed by 1H NMR, 13C NMR, and HRMS analysis. The biological activities were evaluated in vitro. Their JAK2 inhibitory activities were studied using JAK2 enzymatic and TF1-GMCSF cellular assays. The results indicated that compounds 12b , 12e and 12h showed moderate activity. The anti-tumor activities were studied against JAK2-independent A549 cell line by the MTT assay. Results showed that the title compounds exhibited potent antiproliferative effect on A549, especially compound 12c (IC50=0. 12 μmol/L), suggesting that this series compounds might be promising anti-tumor agents for futher investigation.
2017, 48(2): 157-166.
DOI: 10.11665/j.issn.1000-5048.20170205
Abstract：
A series of 5H-benzo［b］carbazole derivatives were synthesized to find new TopII inhibitors. The substitution pattern at C-9 was discussed. All 16 compounds were tested for their antiproliferative activities against 4 tumor cell lines(SMMC-7721, S1, HCT116, and HeLa)by sulforhodamine B assay. Four compounds were found to inhibit the proliferation of all tested cell lines. And compound 10e displayed the best antiproliferative activity against all 4 tested cell lines with IC50 values of 5. 06, 4. 50, 5. 29, and 6. 32 μmol/L, respectively.
A series of 5H-benzo［b］carbazole derivatives were synthesized to find new TopII inhibitors. The substitution pattern at C-9 was discussed. All 16 compounds were tested for their antiproliferative activities against 4 tumor cell lines(SMMC-7721, S1, HCT116, and HeLa)by sulforhodamine B assay. Four compounds were found to inhibit the proliferation of all tested cell lines. And compound 10e displayed the best antiproliferative activity against all 4 tested cell lines with IC50 values of 5. 06, 4. 50, 5. 29, and 6. 32 μmol/L, respectively.
Abstract：
To explore a new strategy for further optimization to the C-3 bioisteric heterocyclic ring of fluoroquinolones, twelve novel fluoroquinolone C-3 s-triazole Schiff-base carboxylic acid derivatives( 7a - 7l )were designed and synthesized with both functionalized sulfanylacetic acid and Schiff-base moieties as the modified side-chain for the C-3 bioisosteric s-triazole ring of pefloxacin( 1 ). The structures were characterized by elemental analysis and spectral data, and the in vitro anti-tumor activity of the title compounds against SMMC-7721, L1210 and HL60 cell lines was evaluated. The preliminary pharmacological results demonstrated that the title compounds possessed more significantly anti-proliferative activity than either the parent 1 or the corresponding amine intermediates( 6 ). In particular, the title compound bearing a fluorine atom( 7j )and compound bearing a nitro group attached to benzene ring( 7l )were comparable to the control doxorubicin against SMMC-7721 cells with an IC50 value of micro-molar concentration, respectively. It suggests that s-triazole ring modified with functional side-chain moieties instead of the C-3 carboxylic group is favorable to the improvement of antitumor activity.
To explore a new strategy for further optimization to the C-3 bioisteric heterocyclic ring of fluoroquinolones, twelve novel fluoroquinolone C-3 s-triazole Schiff-base carboxylic acid derivatives( 7a - 7l )were designed and synthesized with both functionalized sulfanylacetic acid and Schiff-base moieties as the modified side-chain for the C-3 bioisosteric s-triazole ring of pefloxacin( 1 ). The structures were characterized by elemental analysis and spectral data, and the in vitro anti-tumor activity of the title compounds against SMMC-7721, L1210 and HL60 cell lines was evaluated. The preliminary pharmacological results demonstrated that the title compounds possessed more significantly anti-proliferative activity than either the parent 1 or the corresponding amine intermediates( 6 ). In particular, the title compound bearing a fluorine atom( 7j )and compound bearing a nitro group attached to benzene ring( 7l )were comparable to the control doxorubicin against SMMC-7721 cells with an IC50 value of micro-molar concentration, respectively. It suggests that s-triazole ring modified with functional side-chain moieties instead of the C-3 carboxylic group is favorable to the improvement of antitumor activity.
2017, 48(2): 172-177.
DOI: 10.11665/j.issn.1000-5048.20170207
Abstract：
New process reported the synthesis of telavancin using decyl alcohol as the starting material. After methanesulfonylation, nucleophilic substitution with ethanolamine, Fmoc protection, and Parikh-Doering oxidation, the intermdiate N-(9-fluorenyl-9-methoxycarbonyl)decylaminoethyl acetaldehyde( 5 )was obtained. Vancomycin hydrochloride and intermediate 5 were then subject to reductive amination reaction, Fmoc deprotection, and Mannich reaction to give the telavancin product. The process have been deeply studied on the two key reactions of reductive amination and Mannich reaction, and the reaction conditions have been optimized. The overall yield is 46% based on starting material vancomycin.
New process reported the synthesis of telavancin using decyl alcohol as the starting material. After methanesulfonylation, nucleophilic substitution with ethanolamine, Fmoc protection, and Parikh-Doering oxidation, the intermdiate N-(9-fluorenyl-9-methoxycarbonyl)decylaminoethyl acetaldehyde( 5 )was obtained. Vancomycin hydrochloride and intermediate 5 were then subject to reductive amination reaction, Fmoc deprotection, and Mannich reaction to give the telavancin product. The process have been deeply studied on the two key reactions of reductive amination and Mannich reaction, and the reaction conditions have been optimized. The overall yield is 46% based on starting material vancomycin.
2017, 48(2): 178-183.
DOI: 10.11665/j.issn.1000-5048.20170208
Abstract：
A qualitative analytical method of liquid chromatography coupled with ion trap time-of-flight mass spectrometry(LC-IT-TOF/MS)was developed for identification of major constituents in propolis from China(Shandong). The LC-IT-TOF-MS was performed on a Shim-pack VP-ODS column(2. 0 mm×150 mm, 5 μm)with the mobile phase consisting of acetonitrile and water containing 0. 2% formic acid in gradient mode, and the flow rate was set at 0. 3 mL/min. Negative ion mode was used for IT-TOF-MS. According to the accurate molecular weight, MS fragment pathway, comparison with the retention time of reference compounds, total 31 compounds, including twenty-five phenolic acids and six flavonoids were identified. The LC-IT-TOF-MS qualitative analysis method can be used for analyzing major components of propolis quickly and accurately.
A qualitative analytical method of liquid chromatography coupled with ion trap time-of-flight mass spectrometry(LC-IT-TOF/MS)was developed for identification of major constituents in propolis from China(Shandong). The LC-IT-TOF-MS was performed on a Shim-pack VP-ODS column(2. 0 mm×150 mm, 5 μm)with the mobile phase consisting of acetonitrile and water containing 0. 2% formic acid in gradient mode, and the flow rate was set at 0. 3 mL/min. Negative ion mode was used for IT-TOF-MS. According to the accurate molecular weight, MS fragment pathway, comparison with the retention time of reference compounds, total 31 compounds, including twenty-five phenolic acids and six flavonoids were identified. The LC-IT-TOF-MS qualitative analysis method can be used for analyzing major components of propolis quickly and accurately.
2017, 48(2): 184-195.
DOI: 10.11665/j.issn.1000-5048.20170209
Abstract：
With citric acid as carbon source and different amino acids as nitrogen source, the nitrogen-doped carbon was synthesized by one-step hydrothermal method under the condition of no catalyst. The pre-experiments show that arginine-doped carbon dots(CDs-Arg)with relatively high fluorescence quantum yield(33. 25%)were picked out for further study. Furthermore, we studied the physical and chemical properties of CDs-Arg through a series of spectral, electric potential, particle size, X ray and elemental analysis experiments. At the same time, the stabilities of the nanoparticles towards different pH, temperatures, excitation lasers or redox conditions were studied. And the MTT and in vivo distribution experiments were also conducted for the toxicity and metabolism studies. The experimental results showed that the arginine doped carbon dots has high fluorescence efficiency, good stability, and extremely low toxicity. And the water-soluble small particles of CDs-Arg nanoparticles showed that the nanoparticles can be excreted through the glomerulus. These results show that the CDs-Arg Nanoparticles are biocompatible nanoparticles and have potential applications in biological imaging and can serve as a monitor of drug metabolism.
With citric acid as carbon source and different amino acids as nitrogen source, the nitrogen-doped carbon was synthesized by one-step hydrothermal method under the condition of no catalyst. The pre-experiments show that arginine-doped carbon dots(CDs-Arg)with relatively high fluorescence quantum yield(33. 25%)were picked out for further study. Furthermore, we studied the physical and chemical properties of CDs-Arg through a series of spectral, electric potential, particle size, X ray and elemental analysis experiments. At the same time, the stabilities of the nanoparticles towards different pH, temperatures, excitation lasers or redox conditions were studied. And the MTT and in vivo distribution experiments were also conducted for the toxicity and metabolism studies. The experimental results showed that the arginine doped carbon dots has high fluorescence efficiency, good stability, and extremely low toxicity. And the water-soluble small particles of CDs-Arg nanoparticles showed that the nanoparticles can be excreted through the glomerulus. These results show that the CDs-Arg Nanoparticles are biocompatible nanoparticles and have potential applications in biological imaging and can serve as a monitor of drug metabolism.
Abstract：
A method based on in situ formed ionic liquids microextraction-ultra performance liquid chromatography(ISFILM-UPLC)was established for the determination of vancomycin in human serum. The samples were pretreated by vortex and centrifugation. ［C6MIM］［Br］ and NaPF6 were applied as the extracting agent, and Metronidazole as the internal standard. Methanol was applied to redissolve the precipitate. The separation was carried out on a BEH C18 column, and the mobile phase consisted of methanol and 0. 05 mol/L monopotassium phosphate solution. The flow rate was 0. 2 mL/min, the injection volume was 5 μL, and the column temperature was 18 °C. The key parameters of this method such as the specificity, accuracy and precision were validated. This method showed good correlation with the immunoassay. It shows great potential for the application in clinical practice.
A method based on in situ formed ionic liquids microextraction-ultra performance liquid chromatography(ISFILM-UPLC)was established for the determination of vancomycin in human serum. The samples were pretreated by vortex and centrifugation. ［C6MIM］［Br］ and NaPF6 were applied as the extracting agent, and Metronidazole as the internal standard. Methanol was applied to redissolve the precipitate. The separation was carried out on a BEH C18 column, and the mobile phase consisted of methanol and 0. 05 mol/L monopotassium phosphate solution. The flow rate was 0. 2 mL/min, the injection volume was 5 μL, and the column temperature was 18 °C. The key parameters of this method such as the specificity, accuracy and precision were validated. This method showed good correlation with the immunoassay. It shows great potential for the application in clinical practice.
Abstract：
This study was to investigate the inhibitory effects of artemether in combination with etoposide on the proliferation and invasion ability of human small cell lung cancer cell line H446. H446 cells were treated with different concentrations of artemether or etoposide alone or their combination. The inhibitory effects on proliferation were detected by MTT assay, while cell cycle and apoptosis of H446 cells in each group were analyzed by flow cytometry using PI and Annexin V/PI-staining, respectively. The invasion capability of H446 cells in different groups was tested with matrigel-coated transwell. The results implicated that artemether or etoposide or their combination does inhibit proliferation of H446 cells dose-dependently. Artemether alone had little effect on the apoptosis of H446 cells while its combination with etoposide resulted in significantly apoptosis of H446 cells comparing with other groups(P< 0. 05). Etoposide blocked H446 progression markedly by arresting cell cycle in G2 phase with percentage of cells in G1 phase decreasing significantly while artemether alone or in combination with etoposide had little synergetic effect on cell cycle. Artemether or etoposite alone or their combination could dramatically inhibit the invasion ability of H446 cells.
This study was to investigate the inhibitory effects of artemether in combination with etoposide on the proliferation and invasion ability of human small cell lung cancer cell line H446. H446 cells were treated with different concentrations of artemether or etoposide alone or their combination. The inhibitory effects on proliferation were detected by MTT assay, while cell cycle and apoptosis of H446 cells in each group were analyzed by flow cytometry using PI and Annexin V/PI-staining, respectively. The invasion capability of H446 cells in different groups was tested with matrigel-coated transwell. The results implicated that artemether or etoposide or their combination does inhibit proliferation of H446 cells dose-dependently. Artemether alone had little effect on the apoptosis of H446 cells while its combination with etoposide resulted in significantly apoptosis of H446 cells comparing with other groups(P< 0. 05). Etoposide blocked H446 progression markedly by arresting cell cycle in G2 phase with percentage of cells in G1 phase decreasing significantly while artemether alone or in combination with etoposide had little synergetic effect on cell cycle. Artemether or etoposite alone or their combination could dramatically inhibit the invasion ability of H446 cells.
Abstract：
To investigate the effect of estrogen receptor(ER)agonist 17β-estradiol and G protein-coupled estrogen receptor 1(GPER)agonist fulvestrant on masangial cell fibrogenesis under protein kinase C(PKC), we quantified type IV collagen(COL4A1), fibronectin(FN1), connective tissue growth factor(CTGF)and transforming growth factor-β1(TGFβ1)gene transcription and semi-quantified phosphorylation of Akt signal upon Phorbol 12-myristate 13-acetate stimulation(which increased COL4A1, FN1, CTGF and TGFβ1 gene transcription to 2. 5±0. 5, 1. 4±0. 2, 26±11 and 1. 9±0. 3 times compared with baseline, P< 0. 05)when incubated with the two drugs. It was found that 17β-estradiol and fulvestrant down-regulated COL4A1, FN1, CTGF and TGFβ1 genes transcription(P< 0. 05)and Akt signaling under PKC activation via ER and GPER. ER and GPER agonists are beneficial in protecting the mesangial cells from fibrogenic stimuli by inhibiting PKC signaling and excessive extracellular matrix production.
To investigate the effect of estrogen receptor(ER)agonist 17β-estradiol and G protein-coupled estrogen receptor 1(GPER)agonist fulvestrant on masangial cell fibrogenesis under protein kinase C(PKC), we quantified type IV collagen(COL4A1), fibronectin(FN1), connective tissue growth factor(CTGF)and transforming growth factor-β1(TGFβ1)gene transcription and semi-quantified phosphorylation of Akt signal upon Phorbol 12-myristate 13-acetate stimulation(which increased COL4A1, FN1, CTGF and TGFβ1 gene transcription to 2. 5±0. 5, 1. 4±0. 2, 26±11 and 1. 9±0. 3 times compared with baseline, P< 0. 05)when incubated with the two drugs. It was found that 17β-estradiol and fulvestrant down-regulated COL4A1, FN1, CTGF and TGFβ1 genes transcription(P< 0. 05)and Akt signaling under PKC activation via ER and GPER. ER and GPER agonists are beneficial in protecting the mesangial cells from fibrogenic stimuli by inhibiting PKC signaling and excessive extracellular matrix production.
2017, 48(2): 214-219.
DOI: 10.11665/j.issn.1000-5048.20170213
Abstract：
In order to study the relationship between Staphylococcal nuclease(SNase)and diabetes mellitus, genetic engineering bacteria E. coli BL21/pET28a-His-SNase was constructed, the expression of soluble extracellular protein SNase was induced and the a preliminary research was made on it. An expression vector pET28a-His-SNase plasmid containing the His-SNase gene was constructed and transformed into E. coli BL21(DE3)competent cells. The protein was induced by lactose and purified by ultrasound destruction and Ni-affinity chromatography, respectively. It was then analyzed by SDS-PAGE and Western blot. The enzymatic properties for SNase has been preliminary studied as well. Results indicated that the purity of the correctly expressed fusion protein His-SNase was over 85%. SNase showed good activity within a wide range of pH and good heat resistance. This experiment might be a foundation work for the further study on the relationship between SNase and with diabetes.
In order to study the relationship between Staphylococcal nuclease(SNase)and diabetes mellitus, genetic engineering bacteria E. coli BL21/pET28a-His-SNase was constructed, the expression of soluble extracellular protein SNase was induced and the a preliminary research was made on it. An expression vector pET28a-His-SNase plasmid containing the His-SNase gene was constructed and transformed into E. coli BL21(DE3)competent cells. The protein was induced by lactose and purified by ultrasound destruction and Ni-affinity chromatography, respectively. It was then analyzed by SDS-PAGE and Western blot. The enzymatic properties for SNase has been preliminary studied as well. Results indicated that the purity of the correctly expressed fusion protein His-SNase was over 85%. SNase showed good activity within a wide range of pH and good heat resistance. This experiment might be a foundation work for the further study on the relationship between SNase and with diabetes.
Abstract：
A cDNA library was constructed from glands of wild Buthus martensii Karsch scorpion. A new sodium channel long-chain toxin BmkNaTx12 was identified by sequence alignment, and its full-length cDNA sequence was cloned. Sequence alignment showed that the sequence of BmkNaTx12 had high structural similarity with the β-toxin Cn12 from Mexican Centruroides noxius scorpion. The predicted structure of BmkNaTx12 was obtained by homologous model construction and the highest scoring model was selected. The protein structure was found to be stable at 300 ns by molecular dynamics optimization, and fluctuations at amino acids 20, 35, and 52 are most likely due to the location of these amino acids in the loop region. Then, an expression system of recombinant BmkNaTx12-Fc fusion protein was constructed. The optimal expression time of recombinant protein was determined by Western blot and the fusion protein was successfully expressed in HEK293 cells. The purity of recombinant fusion protein which was obtained by protein A affinity chromatography was up to 95% by SDS-PAGE gel electrophoresis and HPLC. In addition, the whole-cell patch-clamp assay results suggest that 1 μmol/L BmkNaTx12-Fc can increase 20% Nav1. 7 peak current. These results laid a foundation for the further study of biological function.
A cDNA library was constructed from glands of wild Buthus martensii Karsch scorpion. A new sodium channel long-chain toxin BmkNaTx12 was identified by sequence alignment, and its full-length cDNA sequence was cloned. Sequence alignment showed that the sequence of BmkNaTx12 had high structural similarity with the β-toxin Cn12 from Mexican Centruroides noxius scorpion. The predicted structure of BmkNaTx12 was obtained by homologous model construction and the highest scoring model was selected. The protein structure was found to be stable at 300 ns by molecular dynamics optimization, and fluctuations at amino acids 20, 35, and 52 are most likely due to the location of these amino acids in the loop region. Then, an expression system of recombinant BmkNaTx12-Fc fusion protein was constructed. The optimal expression time of recombinant protein was determined by Western blot and the fusion protein was successfully expressed in HEK293 cells. The purity of recombinant fusion protein which was obtained by protein A affinity chromatography was up to 95% by SDS-PAGE gel electrophoresis and HPLC. In addition, the whole-cell patch-clamp assay results suggest that 1 μmol/L BmkNaTx12-Fc can increase 20% Nav1. 7 peak current. These results laid a foundation for the further study of biological function.
2017, 48(2): 227-232.
DOI: 10.11665/j.issn.1000-5048.20170215
Abstract：
In order to study the structure-function relationship in the protein which is incorporated with p-nitro-L-phenylalanine, the method of MD(Molecular Dynamics)simulation was established and successfully used in the analysis of protein which contains p-nitro-L-phenylalanine. The force field of CHARMM can only stimulate protein with natural amino acid in NAMD. Compared with phenylalanine, p-nitro-L-phenylalanine just has one more group of nitro. If the parameter of group of nitro was defined, the protein containing p-nitro-L-phenylalanine can be simulated. CGenFF-paramchem was used to calculate the energy and topological structure of p-nitro-L-phenylalanine′s new bonds(r), angles(θ), dihendrals(φ)and improper angle(ψ). And then the new defined parameter and topology information was input into the related parameter files and topology files in CHARMM. On the basis of correct parameter, NAMD can successfully simulate the modified BAFF(B lymphocyte stimulator)which contains p-nitro-L-phenylalanine. The changes in structure indicated that there might be new B cell epitopes. The temperature distribution of each frame in the process of dynamics stimulation was in accord with normal distribution, which proved the defined force field parameters was feasible. The RMSD of whole protein solution systemis 2. 5. Calculate each resides′ RMSF in BAFF, the RMSF of p-nitro-L-phenylalanine′s residue is 3. 7, which is obviously higher than that of the other residues in β-pleated sheet, and close to the loop rings, indicate that there might be variation in the area of p-nitro-L-phenylalanine residue and might produce new comformational epitopes. The results of MD stimulation will guide the immunogenicity experiments of p-nitro-L-phenylalanine modified proteins.
In order to study the structure-function relationship in the protein which is incorporated with p-nitro-L-phenylalanine, the method of MD(Molecular Dynamics)simulation was established and successfully used in the analysis of protein which contains p-nitro-L-phenylalanine. The force field of CHARMM can only stimulate protein with natural amino acid in NAMD. Compared with phenylalanine, p-nitro-L-phenylalanine just has one more group of nitro. If the parameter of group of nitro was defined, the protein containing p-nitro-L-phenylalanine can be simulated. CGenFF-paramchem was used to calculate the energy and topological structure of p-nitro-L-phenylalanine′s new bonds(r), angles(θ), dihendrals(φ)and improper angle(ψ). And then the new defined parameter and topology information was input into the related parameter files and topology files in CHARMM. On the basis of correct parameter, NAMD can successfully simulate the modified BAFF(B lymphocyte stimulator)which contains p-nitro-L-phenylalanine. The changes in structure indicated that there might be new B cell epitopes. The temperature distribution of each frame in the process of dynamics stimulation was in accord with normal distribution, which proved the defined force field parameters was feasible. The RMSD of whole protein solution systemis 2. 5. Calculate each resides′ RMSF in BAFF, the RMSF of p-nitro-L-phenylalanine′s residue is 3. 7, which is obviously higher than that of the other residues in β-pleated sheet, and close to the loop rings, indicate that there might be variation in the area of p-nitro-L-phenylalanine residue and might produce new comformational epitopes. The results of MD stimulation will guide the immunogenicity experiments of p-nitro-L-phenylalanine modified proteins.
2017, 48(2): 233-241.
DOI: 10.11665/j.issn.1000-5048.20170216
Abstract：
The cyclin-dependent protein kinase 9(CDK9)is a member of the family of cyclin-dependent protein kinases. Different from other CDKs, CDK9 mainly works on the transcription regulation and has no affects on the cell cycle progress. There are many kinds of CDK9 inhibitors in the clinical research. The detailed structure and action mechanism of CDK9, its difference of protein structure from other CDKs, several selective or nonselective CDK9 inhibitors, as well as their structure-activity relationship(SAR)are discussed in this paper.
The cyclin-dependent protein kinase 9(CDK9)is a member of the family of cyclin-dependent protein kinases. Different from other CDKs, CDK9 mainly works on the transcription regulation and has no affects on the cell cycle progress. There are many kinds of CDK9 inhibitors in the clinical research. The detailed structure and action mechanism of CDK9, its difference of protein structure from other CDKs, several selective or nonselective CDK9 inhibitors, as well as their structure-activity relationship(SAR)are discussed in this paper.
2017, 48(2): 242-250.
DOI: 10.11665/j.issn.1000-5048.20170217
Abstract：
The oral colon-specific drug delivery system(OCDDS)has gained more attention from investigators in recent years since it can increase local drug concentration and reduce dosage and side effects. The type of colon-specific drug delivery system consists of enzyme dependent, pH dependent, time dependent, pressure dependent system and CODEDSTM. The development of many new materials and technology is very important for the preparation of new type of precise positioning colon-specific preparation. This article summarizes the advances in excipients and technique for oral colon-specific drug delivery system in recent years. It may provide a reference and a basis for the researchers concerned.
The oral colon-specific drug delivery system(OCDDS)has gained more attention from investigators in recent years since it can increase local drug concentration and reduce dosage and side effects. The type of colon-specific drug delivery system consists of enzyme dependent, pH dependent, time dependent, pressure dependent system and CODEDSTM. The development of many new materials and technology is very important for the preparation of new type of precise positioning colon-specific preparation. This article summarizes the advances in excipients and technique for oral colon-specific drug delivery system in recent years. It may provide a reference and a basis for the researchers concerned.
